<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>demo</title>
	<script src="jquery-3.4.1.min.js"></script>
<style type="text/css">




</style>
</head>
<body>
	



<script type="text/javascript">

	function $(id){
		return typeof id=== 'string'?document.getElementById(id):null;
	}




</script>


</body>
</html>